Coordinates are a set of values that show an exact position on a plane or a graph. They are a pair of numbers, or sometimes a letter and a number, that locate a specific point on a grid, known as a coordinate plane. The coordinates are taken to be real numbers in elementary mathematics, but may be complex numbers or elements of a more abstract system such as a commutative ring. The order of the coordinates is significant, and they are sometimes identified by their position in an ordered tuple and sometimes by a letter, as in "the x-coordinate".
In primary school, children are taught Cartesian coordinates, which are two numbers that indicate the point on the x-axis (the horizontal axis) and the point on the y-axis (the vertical axis) . A coordinate plane has four quadrants and two axes: the x-axis (horizontal) and y-axis (vertical) . When reading or plotting coordinates, you always go across first and then up.
Coordinates can be used to determine the position of a point or a shape in a particular space, such as a map or a graph. They allow problems in geometry to be translated into problems about numbers and vice versa, which is the basis of analytic geometry. There are different types of coordinates, such as map coordinates (North/South, East/West), polar coordinates (distance, angle), and 3-dimensional coordinates.
